Alternatively, you can enter the desired resolution and Photoshop will recalculate the document size for you. If the resolution is too low, enter a smaller document size. If the resulting resolution falls within the guidelines mentioned earlier, press OK and your photo will be resized accordingly. Next, enter your desired document size into the width field both the height and resolution will change automatically to preserve the aspect ratio (the relationship between width and height). This lets you experiment with document size and resolution without altering the number of pixels your photo contains (which preserves photo quality). The resulting dialog box reveals all kinds of information about your photo such as file size (how much space it takes up on your hard drive), pixel dimensions, and-most importantly for print-the Document Size section that tells you how big the photo would be if you printed it at its current resolution.įirst, you need to lock your photo’s pixel dimensions by turning off the Resample Image checkbox at the bottom of the dialog box. You can summon this dialog box in Adobe Photoshop (any version) by opening a photo and choosing Image -> Image Size (in Photoshop Elements, choose Image -> Resize -> Image Size, or press Command-Option-I in either program). If you were to print this image, you’d need a piece of paper that’s over 40-by-30 inches! Luckily, by increasing resolution you can make the pixels smaller, which results in a smaller document size.
(For example, if you used a lower quality setting on your camera, your image may not contain enough pixels to print an 8-by-10-inch photo at high resolution.)
This dialog box is also handy for learning how big you can print your image at a given resolution. If your image doesn’t need to be cropped, you can use the Image Size dialog box for resizing.
If you’re printing on an inkjet printer at home, your resolution should fall somewhere between 240 and 480 ppi if you’re using glossy or matte paper, or 180 and 240 ppi for regular or textured paper. This involves increasing the resolution beyond that at which your camera was set (typically 72 or 150 ppi, depending on the model and manufacturer). The goal in printing is to make the pixels too small to be seen individually (otherwise the print will look blocky). The next number refers to pixel size and, as discussed in our image resolution primer, resolution is the measurement that controls it.